Fix sli/core docs directory

Docs directory for sli/core was not in the right place and so was not
being included in readthedocs

Change-Id: I934097fe65721fcd8e7447b095cce7a0a20e3714
Issue-ID: CCSDK-140
Signed-off-by: Dan Timoney <dtimoney@att.com>
8 files changed